Add changelog entry

Author: blacelle

CHANGES.md

@@ -10,6 +10,8 @@ This document is intended for Spotless developers.
 We adhere to the [keepachangelog](https://keepachangelog.com/en/1.0.0/) format (starting after version `1.27.0`).
 
 ## [Unreleased]
+### Changes
+* Bump default `cleanthat` version to latest `2.13` -> `2.16`. ([#1725](https://github.com/diffplug/spotless/pull/1725))
 
 ## [2.39.0] - 2023-05-24
 ### Added